User guide

HARD Battery Volts 12.4 to 12.8 Volts Checks battery state of charge. Below 12.3V, charge
START (Engine Off) is low, or load may be on.
Ignition Energy More than 20 mVSec Shows that there is coil energy available to start
(Cranking) the engine.
CHARGING Battery Volts 13.2 to 15.2 Volts Shows the voltage regulator setting and
STARTING (Engine Running) if the alternator functions.
Amps Ripple None If alternator has a bad diode or stator a message will
(Engine Running) appear.
IGNITION Ignition Energy 35-55 mVSec Checks for faulty coils, and driver modules.
PRIMARY (Engine Running)
Dwell 60% w/ Ballast Adjust as necessary.
(Engine Running) 3 to 4 mSec current limited Checks ignition modules.
Dwell Variation 3.0° or less Checks primary ignition system performance.
(Engine Running) Test from Idle to Cruise RPM.
Timing Variation 3.0° or less Shows ignition timing irregularity if too high.
(Engine Running)
Driver Voltage Electronic less than 1.5V Shows coil driver module, and module ground
(Engine Running) Points less than 0.3V resistance if too high.
Coil Oscillations Electronic 1 to 4 Osc Checks for shorts in coil insulation or connected
(Engine Running) Points 4 to 8 Osc components.
SPARK Burn Time Average 0.8 to 2.3 mSec Checks condition of secondary ignition system
BURN (Engine at Idle) Finds open or grounded spark plug wires.
Burn Time Minimum more than 0.8 mSec Shows worn or wide gap plugs if less.
(Accelerate Engine)
Burn Time Maximum less than 2.3 mSec Finds grounded plugs or wires. Locates ignition misfires.
Burn Slope -30 to +30 Lean mix or wide plug gap if 20 greater than average.
Rich mix or high resistance plug if 20 less than average.
CRANKING Cranking Volts 9.6 to 12 Volts Checks battery and starter condition performance.
ANALYSIS
Cranking Amps 100 to 300 Amps High amps, possible bad starter.
Low amps, possible bad connections, or bad battery.
Cranking RPM Over 150 RPM Checks starter performance.
Alternator Amps 50 to 100 Amps Compare alternator output to specs.
Battery CCA est. 300 to 600 CCA If 20% lower than the rating on the battery,the
Compare to Battery Spec's battery is weak and may be ready for replacement.
Amps Peak Less than 5 percent Probably low compression, if more than 8%.
POWER %RPM drop when each 5 to 15% within 2:1 ratio The higher the number the stronger the cylinder. A
BALANCE cylinder is shut off negative number means the engine speed increased.
FUEL Port Injection 0.4 to 20 mSec Measures on-time of the injector drive.
INJECTION
Solenoid Duty 30° to 60° M/C, 10 Hertz Checks function of mixture control solenoid.
SENSOR Throttle Position Sensor 0.5 to 5V with no glitches Checks function of throttle position sensor.
TEST
Oxygen Sensor 0.45V & over 1 Cross./Sec. Checks activity of the oxygen sensor.
Ohmmeter 1 to 50K Ohm Measures resistance to ground.
Diode Volts 0.5 to 0.7 Volts Measures diode forward voltages.
Test Key Measurement Typical Readings Interpretation
Note: Use repair manuals and compare similar engines to obtain actual specifications.
Typical readings shown apply to most normal vehicles.